New engines highlight changes

Originally published: April 21, 2010

SMALL

MEDIUM

LARGE

Miami: Cosmetically, the new X5’s mid-life makeover is very subtle. For the record, the outward appearance changes include repositioned fog lights, revised headlights, redesigned under-bumper air intakes, matte silver inserts in the front chin spoiler and lower rear valance, restyled tail lights, reshaped exhaust tips and — wait for it — an increased number of body-coloured adornments. It really does take a side-by-side comparison to appreciate the differences.

Inside, there are no changes other than the addition of a few electronic gadgets — adaptive cruise control with a stop-and-go function (it functions in stop-and-go traffic) and side-view and top-view cameras. The combination delivers a bird’s-eye view and allows the driver to see left and right. The other add-on is a lane departure warning system. On the drive route, it proved to be as much an annoyance as a help because of the haptic feedback — the steering wheel vibrates for several seconds beyond what’s needed. I have no complaints with the head-up display. It is clear, concise and very handy, and the navigation system’s inset is particularly welcome.

Where the 2011 X5 strikes out anew is with two new powertrains that feature upgraded gasoline engines and an eight-speed manumatic transmission, which dramatically transform the luxury sport-ute’s driving dynamics.

The X5 xDrive35d continues with its sweet diesel engine. The 3.0-litre twin-turbo delivers 265 horsepower and 425 pound-feet of torque. Sadly, it makes do with the existing six-speed automatic.

The X5 xDrive50i, which replaces the X5 xDrive48i, promises to be about as subtle as brass knuckles — at least if its performance mirrors that of the X6. Last year’s 4.8L V8 was no slouch, putting 350 hp and 350 lb-ft of torque at the driver’s right foot. The new engine outdoes it in every area.

The stallion count rises to 400, torque jumps to 450 lb-ft and the time needed to reach 100 kilometres an hour drops by 1.3 seconds to 5.6 seconds.

The vehicles that were available for testing all featured BMW’s new 3.0L turbocharged in-line six. Now, don’t confuse this engine with the 3.0L twin-turbo found in the likes of the 135i and 335i. This engine differs as it combines the benefits of a single, twin-scroll turbocharger (one scroll is fed by cylinders 1, 2 and 3, while the second is fed by the remaining cylinders) with direct fuel injection and Valvetronic. The latter dispenses with the throttle and uses the intake valves to control engine output and speed.

The efficiency gains are enormous. When compared with the outgoing X5 xDrive 30i, the X5 xDrive35i develops 15% more power (up to 300 hp), 33% more torque (300 lb-ft) and it’s a whopping 1.6 seconds faster to 100 kilometres an hour. This drop to 6.8 seconds means the new six is 1/10th of a second quicker than the outgoing V8. That is a quantum improvement.

Although official fuel economy numbers are not available, BMW promises the new six will deliver the performance while consuming less fuel. Bonus.

The long looping drive around the Miami area and out into the Everglades proved the engine’s promise — as it appears on paper — translated into an exceptional on-road driving experience. Where the new engine really shines is in the torque department. This engine slams its 300 lb-ft to the pavement at just 1,200 rpm, which is diesel-like. Combine this with the eight-speed transmission’s easygoing demeanour and the annoying (and generally unwanted) gear shifts that come whenever the driver breathes on the gas pedal all but disappear. Talk about a totally effortless drive.

Conversely, mat the gas from a standstill and the power instantly comes on-line, with no turbo lag. Keep the pedal buried and the X5 steps out with surprising authority as the transmission snicks up through the gears. The advantage in having eight speeds is that six of them are used to keep the engine in its sweet spot, which maximizes performance. The final two gears provide quiet highway cruising and improve overall fuel economy.

As for the ride and handling characteristics, the X5 retains its accomplished balance. The proactive nature of the all-wheel-drive system has been tweaked slightly, but its distribution remains biased toward the rear (40/60 front to rear under normal conditions). The suspension delivers a cossetting ride, there’s little in the way of unwanted body motion and the response to steering input is excellent.

Part of the drive involved off-roading, Florida style. After driving down a cottage-like access road, the X5 was forced to wade through water. At times, the wet stuff lapped over the side sills as the tailpipes disappeared into the water. While it wasn’t really a true test of the X5’s off-road mettle, it did demonstrate that this swanky rig will go where most crossovers fear to tread.

Mechanically, the 2011 X5 is significantly better than the model it replaces. As such, convincing a prospective customer that the upgrades are worthwhile will be a simple matter. However, convincing a current owner to trade up to the latest model based solely on its appearance will be much more difficult.